We sincerely thank Tom Pettigrew and Matt Stahl for constructing the PCS; Matt Stahl, Jürgen Hohnberg, and Masa Kawasaki for operating the PCS during core collection; Hermann Wehner for collecting many PCS gas samples; Per Egeberg and Regis Thiery for discussions regarding chemistry; and Ben Clennell and an anonymous reviewer for comments on the original manuscript. We also thank all scientists, engineers, and technicians who have worked previously with the PCS and PCB: our successes with the PCS are the cumulative result of significant work by many others. G. Dickens, P. Wallace, C. Paull, and W. Borowski were funded by the Joint Oceanographic Institutions U.S. Science Support Program. G. Dickens especially thanks all concerned for the last-minute invitation (gamble) to sail on Leg 164 and work on the PCS.